RESUMO
Objective To explore the methylation status of hMLH1 and hMSH2 promoter region in the epithelial ovarian cancer and its role in oncogenesis.Methods Methylation status of hMLH1 and hMSH2 promoter region was assayed in 20 normal ovarian tissues,25 benign epithelial tumor,56 malignant epithelial tumor and cell lines SKOV3,3AO by methylation-specific PCR (MSP).SKOV3 and 3AO were analyzed before and after 5-aza-2′-deoxycytidine (5-Aza-CdR) treatment.In addition,an alterations of mRNA expression of hMLH1 and hMSH2 was observed by reverse transcription polymerase chain reaction (PT-PCR).Results No methylation of hMLH1 and hMSH2 promoter was found in normal ovarian tissues. CPG islands methylation of hMLH1 and hMSH2 was observed in 4% (1/25),8% (2/25) respectively in benign epithelial tumor,30.4% (17/56),51.8% (29/56) respectively in malignant epithelial tumor. Methylation status in promoter showed obvious correlation with pathological grade and lymph node metastasis (P